Modulating Electronic Structures of Noble-Metal Nanoclusters via Interfacial Electron Capture in Heterojunctions for Enhanced Hydrogen Evolution in Wide-pH Region

Designing noble-metal-based heterojunction catalysts with tailored electronic structures is pivotal for achieving exceptional electrocatalytic performance. We developed a versatile strategy to anchor noble-metal nanoclusters (∼1.7 nm) on MoC nanoparticles (M-MoC, M = Ru, Pt, Ir) for an efficient pH-universal hydrogen evolution reaction (HER). Through a controlled thermal-treatment process under inert conditions, heterojunctions leveraging strong metal-support interactions was obtained to fine-tune electronic configurations. DFT calculations demonstrate significantly stronger Ru adsorption on Mo- and C-terminated MoC surfaces compared to carbon, driven by robust Ru-Mo and Ru-C interactions, ensuring nanocluster dispersion and stability. UPS and DFT confirm electron transfer from MoC to Ru, forming a Mott-Schottky heterostructure that optimizes charge redistribution and stabilizes low-valence Ru sites. Ru-MoC achieves ultralow overpotentials in alkaline, neutral, and acidic media, respectively, outperforming most recently reported Ru-based catalysts. Mechanistic studies reveal dual-interface sites that synergistically balance water dissociation and hydrogen adsorption, accelerating the Volmer step and enhancing catalytic efficiency.